class_docstr: The MAC at the end of each epoch computed on a
  single pattern.
  This plugin metric only works at training time.
  
  The MAC will be logged after each training epoch.
code: def __str__(self):
      return "MAC_Epoch"
  
imports: from torch.nn import Module
  from typing import List, Optional
  from torch import Tensor
  from avalanche.evaluation import Metric, PluginMetric, GenericPluginMetric
label_desc: Use image node_id 2 for calling the EpochMAC obj's underlying member method code with example usage: obj.__str__() and returns: str